• Title/Summary/Keyword: butane

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A development of neural-network based gas recognition system using sensor array (센서 어레이를 이용한 신경망 기반의 가스 인식 시스템 개발)

  • 김영진;정종혁;강상욱;조영창
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2002.06a
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    • pp.356-360
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    • 2002
  • Polluting the air with such pollutants as CO, H₂S and SO₂, industrial development huts increased the danger of gas toxication. Futhermore, as the: living standard goes higher, the consumption of explosive hydrocarbonic gases such as butane(C₄H/sub 10/) or propane(C₃H/sub 8/) has been soaring, which results in the danger of a gas explosion. As measures to cope with such dangers, the development of highly sensitive gas sensors, gas detectors adopting gas-sensing technologies, and gas recognition systems are urgently required. The objective of the present research is to develop a gas recognition system that is capable of identifying specific types of selected gases by formulating a semiconductor-typed gas sensor array, which not only improves the selectivity of semiconductor-typed gas sensors but also minimizes the erect of drifts on a single sensor signal, and applying the input pattern data of gases detected by the array to a neural network.

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A Study on Drug Abuse and the Factors Affecting Drug Abuse Behaviors of Students Preparing College Entrance or Transfer Examinations (대입 재수생 및 편입준비생의 약물남용 실태와 이에 영향을 미치는 요인)

  • 조태현;남철현
    • Korean Journal of Health Education and Promotion
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    • v.17 no.2
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    • pp.57-73
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    • 2000
  • A study on drug abuse of young people who failed in college entrance examinations and preparing the next examination and those enrolled at colleges but trying to transfer to other colleges was conducted from February 3 to May 31, 1999 in order to determine current drug abuse status of them and factors affecting their behavior related to drug abuse. A total of 1,771 people were selected from college entrance preparation institutes in Seoul, Pusan, Taegu, Taejon and Kwangju and interviewed by using questionnaires. The results are summarized as follows; 1. 49.78% of them experienced drinking, 22.8% smoking, and 6.7% drug previously. More males smoked cigarettes than females. The young in the age group of 25 to 29 years old, and the young living in small towns, and subjects who finished junior colleges and those without religions drank more than those in other categories. The subjects in the age group of 20 to 24 years old and those with one parent, and those living in small towns used more drugs than those in other categories. 2. 60.1% of those with drug using experience used the drug in their or friends' homes. 53.6% of them used drugs with their friends, junior or senior classmates. 36.6% of them purchased drugs from drug stores. 76.0% of them spent their pocket money for buying drugs. 3. The drugs (excluding alcohol and tobacco) they used were bond and butane gas (29.6%), stimulants (20.6%), marijuana 02.0%) LSD (4.8%), cocaine, heroine and opium (4.2%), and others (28.8%). 4. 21.5% of those with drug using experience had detoxification treatment previously. The ajmor sufferings they experienced were distraction (42.6%), fear 01.7%), and others. 5. 51.0% of the subjects experienced drug related health education in schools, and 14.6% had that kind of education through social program. 6. 64.3% of the subjects got information about drug abuse through mass media, 16.4% through printed materials, and 11.4% through public health professionals. 7. The knowledge level of drug abuse was 16.48:1:2.76 points out of 24 (68.6 points out of 100).

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Safety Enhancement of LPG Terminal by LOPA & SIF Method (LOPA 및 SIF기법에 의한 LPG 인수기지의 안전성향상에 대한 연구)

  • Lee, Il Jae;Kim, Rae Hyun
    • Korean Chemical Engineering Research
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    • v.53 no.4
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    • pp.431-439
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    • 2015
  • The methods which decrease the accident hazards of LPG(Liquefied Petroleum Gas) terminal on the basis of butane & propane storage tanks by applying HAZOP(Hazard and Operability), LOPA(Layer of Protection Analysis) and SIL(Safety Integrity Level) are suggested. The accident scenarios were derived by analyzing latent risks through the HAZOP. The scenarios which would have the big damage effect in accidents were selected and then LOPA was assessed by analyzing IPL(Independent Protection Layer) about the correspond accident scenarios. The improved methods were proposed on the basis of level of SIF(Safety Instrumented Functions) as a IPL considering satisfied condition of risk tolerance criteria($1.0{\times}10^{-05}/y$). In addition, The proposed IPLs were basis on the economic analysis. The effect of SIF as a IPL considering the changes of accident frequency was studied in case of the accident scenarios derived from the concerned process.

Process of the Selective Production of 1-Butene through Positional Isomerization from 2-Butenes (2-부텐으로부터 위치 이성화 반응을 통한 선택적 1-부텐의 제조 공정)

  • Ko, MinSu;Jeon, Jong-Ki;Cho, Jungho;Lee, Seong Jun;Lee, Jae Ho
    • Korean Chemical Engineering Research
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    • v.46 no.4
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    • pp.692-696
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    • 2008
  • There is not much method of using C4 Raffinate III, despite having high olefin contents. The majority of the C4 Raffinate III have been converted into n-butane through hydrogenation, and sold as LPG. The C4 Raffinate III is rich 2-butenes with very low isobutene and isobutene contents. The 2-butenes are converted into 1-butene in the vicinity of thermodynamic equilibrium yield through positional isomerization with n-almumina catalyst calcinated at $400{\sim}600^{\circ}C$. The overall process is composed of isomerization-reactor, de-1-buteneizer to prepare the reactants and to enrich reactive products, and 1-butene column to product a high purity 1-butene. The production of 1-butene increases by 40~60 wt% with the selective positional isomerization from the existing separation method.

Heat Transfer Characteristics of R-1270 using 12.7mm Inner Fin Tube (12.7mm 내면핀관을 이용한 R-1270의 열전달 특성)

  • Yoon, Jung-In;Seong, Gwang-Hoon;Shim, Gyu-Jin;Jin, Byoung-Ju;Baek, Seung-Moon;Moon, Choon-Geun
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.4
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    • pp.534-541
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    • 2008
  • This paper deals with the heat transfer characteristics of R-290 (Propane), R-600a (Iso-butane) and R-1270 (Propylene) as an environment friendly refrigerant and R-22 as a HCFC's refrigerant for evaporating. The experimental apparatus has been set-up as conventional vapor compression type refrigeration and air-conditioning system. The test section is a horizontal double pipe heat exchanger. Evaporating heat transfer measurements were performed for smooth tube with the outer diameters of 12.70, 9.52 and 6.35 mm and micro-fin tube 12.70 mm, respectively. For the smooth and micro-fin tubes measured in this study, the evaporating heat transfer coefficient was enhanced according to the increase of the mass flux and decrease of the tube diameter. The local evaporating heat transfer coefficients of hydrocarbon refrigerants were superior to those of R-22 and the maximum increasing rate of heat transfer coefficient was found in R-1270. The average evaporating heat transfer coefficients in hydrocarbon refrigerants showed 20 to 28% higher values than those of R-22. Also, the evaporating heat transfer coefficients of R-22 in the tube diameter of the 12.70 mm smooth and micro-fin tube were compared. Generally, the local heat transfer coefficients for both types of tubes increased with an increase of the mass flux. The heat transfer enhancement factor (EF) between smooth and micro-fin tube varied from 1.9 to 2.7 in all experimental conditions.

Effect of Ignition Delay Time on Autoignited Laminar Lifted Flames (자발화된 층류 부상화염에 대한 점화지연시간의 영향)

  • Choi, Byung-Chul
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.10
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    • pp.1025-1031
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    • 2011
  • Autoignition characteristic is an important parameter for designing diesel or PCCI engines. In particular, diesel spray flames are lifted from the nozzle and the initial flame is formed by an autoignition phenomenon. The lifted nature of diesel spray flames influences soot formation, since air will be entrained into the spray core by the entrainment of air between the nozzle region and the lifted flame base. The objective of the present study was to identify the effect of heat loss on the ignition delay time by adopting a coflow jet as a model problem. Methane ($CH_4$), ethylene ($C_2H_4$), ethane ($C_2H_6$), propene ($C_3H_6$), propane ($C_3H_8$), and normal butane (n-$C_4H_{10}$) fuels were injected into high temperature air, and the liftoff height was measured experimentally. As the result, a correlation was determined between the liftoff height of the autoignited lifted flame and the ignition delay time considering the heat loss to the atmosphere.

Effect of Various Supports on the Catalytic Performance of V-Sb Oxides in the Oxidative Dehydrogenation of sobutane (이소부탄의 산화탈수소반응에 대한 여러 담지체에 따른 V-Sb 산화물 촉매 성능 효과)

  • Shamilov, N.T.;Vislovskiy, V.P.
    • Journal of the Korean Chemical Society
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    • v.55 no.1
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    • pp.81-85
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    • 2011
  • $V_{0.9}Sb_{0.1}O_x$ systems, bulk and deposited on different supports (five types of $\gamma$-aluminas, $\alpha$-alumina, silica-alumina, silica gel, magnesium oxide), have been tested in the oxidative dehydrogenation (ODH) of iso-butane. Catalytic performance of VSb oxides has shown to be highly dependent on the support and the nature of the support decreasing in a series: $\gamma$-$Al_2O_3$ > $\alpha$-$Al_2O_3$ > Si-Al-O > $SiO_2$ $\approx$ MgO $\gg$ unsupported. Variation of the V-Sb-O-loading in the studied range of coverage (0.5-2 theoretical monolayer) only slightly influences the catalysts' activity and selectivity. The best catalytic performance of $\gamma$-alumina-supported $V_{0.9}Sb_{0.1}O_x$ systems can be explained by the optimal surface interaction between support and supported components resulting in the formation of well-spread amorphous active $VO_x$-component with vanadium in a high oxidation state.

The Study on the Attitude about Drugs, the Actual Conditions on Drug Abuse and Drug Education of Primary School Students (국민학생의 약물에 대한 태도와 남용경험 및 약물교육실태)

  • Kim, Jung-Soon
    • Research in Community and Public Health Nursing
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    • v.6 no.2
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    • pp.286-298
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    • 1995
  • The purposes of this study were to suggest the need for drug prevention program in primary school and to provide basic data for preventing the youth from their drug abuse. A total of 680 students of primary school in Pusan were selected to answer this questionnair. The data was collected from July 1 to July 15, 1994. The major findings of this study were as follows : 1) The attitude about drugs of primary school students was desirable. By groups, girl students showed more desirable attitude than boy students. 2) 5.9% of subjects had smoking experience, and for the motives of smoking 77.5% of them, the largest numbers, was with curiosity. 3) 39.8% of subjects had experienced alcohol use, and for the motives alcohol use 50.5% of them, the largest numbers, was with curiosity. 4) 1.8% of subjects had experienced inhalants (gas, butane gas), and for the motives of inhalants use 58.4% of them, the largest numbers, was also with curiosity. 5) The rates of smoking, alcohol use and inhalants use were higher in boy students than girl students. 6) The attitude points about drugs in case of smoking, alcohol use and inhalants use were lower than the points in case of not using them. 7) Knowledge level about .drugs of subjects was appeared poor. 8) For the need of drug education 65.9% of subjects responded 'necessary', and they responded most suitable educator as school nurse. 9) The students had received drug education from school in 38.2%, from their parents in 8% and from mass media in 63.5%.

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Development of Sensor Module and Control System Software for LPG/CNG Stations (LPG/CNG용 센서 모듈 및 관제시스템 S/W 개발)

  • Cho, Beomsek;Kim, Sungkwang;Kim, Sungtae;Kim, Jongmin
    • Journal of the Korean Institute of Gas
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    • v.22 no.1
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    • pp.53-59
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    • 2018
  • In Korea, The number of installed LPG Charging stations is about 2000, increasing by 26 every year. In these, about 500 charging stations are older above 15 year, accounting about 25% of total stations. About 86% of them are located in the city, which is causing serious damage if accident occurs. In this paper, we developed a duel gas sensor module and integrated control system software that can prevent and correspondence to gas leaks and fire accidents at LPG/CNG charging stations. The dual type sensor module has the function of collecting and transmitting the measured data to the sensors of methane, butane and hydrogen through RF433Mhz communication. In addition, each sensor is attached with two to improve stability and accuracy. The integrated control system software detects real-time data of the devices measured by the sensors and it send to the PC and smart phone of manager. Therefore, if accident occurs, the manager can check the status of the charging station regardless of time and place.

Exposure Assessment of Volatile Organic Compounds for Workers Handling Rust-preventive Oils (방청유 취급 근로자의 휘발성 유기화합물 노출 평가)

  • Jeong, Yoonkeong;Choi, Sangjun
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.27 no.1
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    • pp.23-37
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    • 2017
  • Objectives : This study was conducted to evaluate the level of exposure to volatile organic compounds (VOCs) among workers handling rust preventive oils. Methods : A total of 30 bulk samples and 54 personal air samples were collected using diffusive samplers at 22 workplaces handling rust preventive oils in Daegu and Gyongsangbuk-do Province from March to October 2013. We also investigated detailed information on the related work conditions, such as kinds of products, handling methods, local exhaustive ventilation systems, and the status of the wearing personal protective equipment. All bulk samples and air samples were analyzed using gas chromatography mass spectrometry (GC-MS) to identify components to which workers potentially were exposed. Quantitative airborne concentrations of VOCs were confirmed using gas chromatography with flame ionized detectors. Results : In terms of qualitative analyses for the 30 bulk samples, we found carcinogenic, mutagenic and reproductive toxic(CMR) substances such as butane(carcinogenic Group 1A, mutagenic Group 1B), butoxy ethanol(carcinogenic Group 2), cumene (carcinogenic Group 2), ethyl benzene(carcinogenic Group 2), methyl isobutyl ketone(carcinogenic Group 2) and toluene (reproductive toxic, Group 2). As a result of full-shift based personal air samples, eight substances such as n-hexane, n-heptane, octane, nonane, decane, toluene, ethyl benzene and xylene were detected. Among them, n-hexane and n-heptane were detected in all of 54 air samples with $13.13mg/m^3$ and $8.61mg/m^3$ of maximum concentration, respectively. The level of airborne concentration from all of samples were bellow the occupational exposure limit in Korea. Conclusions : Based on the results of this study, workers handling rust preventive oils could be exposed to CMR substances contained in rust preventive oils and n-hexane and n-heptane were found as the most frequent sources of VOC exposure.